Abstract As many as 76% of children with cerebral palsy (CP) have speech and language disorders, including reduced speech intelligibility due to underlying movement deficits. Little research has directly connected the pathophysiology of CP, or underlying disturbance of movement, to the speech deficits observed in this population. Information about how the pathophysiology of CP influences oromotor control in nonspeech and speech tasks is urgently needed to develop efficacious assessment and treatment strategies for this population. The proposed research will directly quantify oromotor performance and control of the lips and jaw to a) identify the impact of CP on the capacity of the oromotor system, b) identify the impact of CP on speech motor performance across tasks varying in linguistic complexity, and c) identify the impact of CP on speech motor control across tasks varying in linguistic complexity. Oromotor performance and control in children with CP will be compared to both typically-developing age-matched and language-matched peers in order to identify the relative contribution of oromotor control and language to speech production of children with CP. Comparisons of the orofacial movements of children with CP in nonspeech and speech tasks to those of their age-matched peers will identify the impact of CP on oromotor performance and control. Comparison of orofacial movements of children in CP with language-matched controls will identify the influence of language skills on speech production in this population. The hypotheses of the proposed research is that orofacial movements of children with CP will be slower, have a restricted range of movement, have longer durations, be more variable, and have reduced movement stability and interarticulator coordination as compared to their typically-developing peers. In addition, it is hypothesized that children with CP use language skills to support speech production. The specific aims that target these hypotheses are: a) to quantify the impact of CP on the capacity of the oromotor system by examining the oromotor performance of the lips and jaw during nonspeech tasks, including chewing and other maximal performance tasks (Aim 1); b) to quantify the speech motor performance (speed, range, duration) of the lips and jaw across tasks varying in linguistic complexity children with CP, their age-matched peers, and language-matched peers (Aim 2); and c) to quantify speech movement stability and interarticulator coordination of children with CP, their age-matched peers, and their language- matched peers across tasks varying in linguistic complexity (Aim 3). Results will be used a) to further classify subgroups of children with CP on the basis of their speech and language skills, and b) as the initial step in identifying aspects of oromotor performance and control that may be targeted for intervention in this population. Findings from the proposed project will also provide insight into the relative contribution of oromotor control and language on speech production and development.